It is known to use mechanical grippers in the shape of fingers for handling containers of photographic emulsions and test samples. Suction devices are also known for handling these materials. Both the mechanical grippers and the suction devices may be pneumatically operated, and as a result, containers containing photographic emulsions and test samples are handled by engagement of the container by these pneumatically-operated devices.
Mechanical grippers in the form of fingers form part of a complicated mechanism which normally only grips a container at a single point. This means that the container may be unbalanced as it is moved from one position to another and its contents may be spilled unless care is taken during handling.
Suction devices handle containers by engaging the inner surface of an upper portion of the container. However, these devices will not hold containers which have been damaged at their upper portion. Furthermore, the reduction in pressure required to operate these devices can affect the contents of the container.